280408020 has 96 divisors (see below), whose sum is σ = 830462976. Its totient is φ = 70579200.

The previous prime is 280407983. The next prime is 280408043. The reversal of 280408020 is 20804082.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 74422 + ... + 78098.

It is an arithmetic number, because the mean of its divisors is an integer number (8650656).

Almost surely, 2^280408020 is an apocalyptic number.

280408020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 280408020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (415231488).

280408020 is an abundant number, since it is smaller than the sum of its proper divisors (550054956).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

280408020 is a wasteful number, since it uses less digits than its factorization.

280408020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3761 (or 3759 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 24.

The square root of 280408020 is about 16745.3880217808. The cubic root of 280408020 is about 654.5308841103.

The spelling of 280408020 in words is "two hundred eighty million, four hundred eight thousand, twenty".